It is common to build multiple implementations of a basic processor architecture for the purpose of providing various performance and pricing options. For example, a processor architecture that supports a particular instruction set may have a first-level cache in one implementation, and another implementation may have first and second level caches.
Some system-provided routines and other library routines are written and compiled to exploit the performance characteristics of a particular implementation of a processor. For example, a memory-to-memory copy routine may be written and compiled differently from one implementation to another. While the binary code will execute correctly on any implementation, there may be a negative impact on performance when the binary code is executed on an implementation other than the target implementation.
A software developer can either develop separate binary libraries for the different implementations, develop a single binary for all implementations, or develop several versions of selected routines along with a run-time switch for selecting between the different versions. Developing separate binary libraries is technically straightforward. However, there is a cost associated with managing and distributing separate binary libraries. If only a single binary library is provided, users may not receive the full performance benefit of a particular implementation. While run-time switches would appear to provide a reasonable tradeoff between the management of multiple binary libraries and performance degradation, the run-time switch introduces overhead when a library call is made to determine the implementation on which the code is executing.
A method and apparatus that address the aforementioned problems, as well as other related problems, are therefore desirable.